The scientific data management CORE has 2 major responsibilities. First, the CORE will recruit, characterize, perform baseline evaluations and be responsible for the interventions common to the individual projects. This includes endurance exercise training (conditioning and deconditioning) and nutrition/weight loss. Second, the CORE poses scientific questions that can be divided into three areas: cross sectional studies, studies pre and post exercise (and diet) interventions and long-term follow up of current TNH subjects. The CORE will characterize the study populations in terms of their exercise capacity and its relationship to age, body composition, level of physical activity as well as motivational and hereditary factors. It will study the ability or inability of middle aged to elderly individuals to train and improve their VO2 max. While VO2 max decreases with aging we hypothesize that older individuals are able to increase VO2 max in response to vigorous endurance training and that inability to alter VO2 max is related to other factors such that as obesity, cardiovascular function and motivation. The CORE will investigate the effects of combined diet and exercise interventions in a group of middle aged to elderly men to determine the interaction between age, body composition and the ability to effectively train and increase VO2 max. It will study the effects of changes in physical activity (exercise for sedentary, rest for the highly conditioned), body weight (hypocaloric feeding) and age (time control) on measures of body composition and their relationship to physiologic and metabolic parameters. Finally, the CORE will study the physiologic and metabolic effects of long term interventions (exercise and diet training) lasting from two to eight years in Sedentary overweight middle aged to elderly men.